As disclosed in EP1903147A3, in such front loaders, some posture maintaining mechanisms (mechanical parallel guide mechanism) are each comprised of a swing link member (three-point swing lever body 5), a base-end link member (link rod 3), a free-end link member (work cylinder 13). The swing link member has two free-end parts and is disposed of a longitudinal central location of a boom so as to be swingable about a third horizontal pivot (three-point swing axis 18) as a fulcrum. The base-end link member is bridged between a fixed bracket (columnar body 4) and one of the free-end parts of the swing link member. The free-end link member links the other free-end part of the swing link member to an implement. With above construction, the front loader operates so as to expand and contract by the interlocking action with the vertical swing of the booms, while maintaining the posture of the implement by the extending-and-contracting operation regardless of the swing displacements of the booms.
In the front loader disclosed in EP1903147A3, each boom (swing boom 2) is formed in a sharply-curved shape where a longitudinal central part thereof is upwardly convex. Meanwhile, the posture maintaining mechanism is configured so that a base-end link member (link rod 3), one of the free-end parts of the swing link member (three-point swing lever body 5) coupled to the base-end link member, etc. are located inwardly from the upper surface of the boom (i.e., on the inside of the boom elbow). Further, the posture maintaining mechanism is configured so that the other free-end part of the swing link member and the free-end link member (work cylinder 13) coupled to the other free-end part, etc. are located outwardly from the upper surface of the boom (i.e., on the outer side of the boom elbow). The other free-end part of the swing link member is configured in a base-end boom part located toward the fixed bracket (columnar body 4) from the bent point of the boom so that the other free-end part greatly projects upwardly from the upper surface of the boom.
With the above configuration, in a low position operating state in which the booms are lowered to a height so that the implement contacts or substantially contacts the ground surface, a field of view of an vehicle operator who rides the vehicle body is significantly interrupted by the other free-end part of the swing link member which greatly projects upwardly from the upper surface of the boom, with one end of the free-end link member coupled to the other free-end part, etc. Therefore, since visibility from the vehicle body side is reduced or impaired in the low position operating state in which the boom is lowered, the low position operation is difficult to perform and, thus, there is a need to improve the operability of the vehicle in the low position operating state.